I’ve been working more on drilling holes in agate for pendants and bead work, and the choice of diamond drill for agate makes a huge difference in hole quality and tool life. Agate’s hardness and banded structure can cause chipping or wandering if the drill geometry, grit, and coolant aren’t dialed in properly.
For those exploring options, here’s a good reference on diamond core drills designed for lapidary and hard stone work:
https://ukam.com/diamond-core-drills-tools-for-lapidary-industry-new/
Curious what point shapes, grit sizes, and speeds others here prefer — and any tips on pressure, cooling technique, or pilot hole use that help reduce breakouts and improve finish.